1. Field of the Invention
The present invention relates to a projection display which is a so-called projector, and a projection display control program applied to such a projection display. In particular, the present invention relates to the projection display equipped with a user interface which enables users to arbitrarily set display modes, and to the projection display control program which realizes such a user-interface.
2. Description of the Related Art
When images are displayed on a liquid crystal display, a certain amount of electric charges are necessarily accumulated in pixels. The accumulated pixels are maintained until next image is displayed so that an image blur caused by a so-called hold effect is generated. In order to improve the resolution of moving images influenced by the hold effect, the following methods have been proposed.
The first method is a so-called black insertion mode in which a black image frame is inserted between a frame F1 and a frame F2 of an original image, for example, as shown in FIG. 10 (refer to Japanese Unexamined Patent Publication No. 2003-186456). The second method is a so-called AB gamma correction mode in which the frame F1 of an original image is transformed into an A gamma correction image F1 (+) which is subjected to a white gamma correction, and a B gamma correction image F1 (−) which is subjected to a black gamma correction, and then the A gamma correction image F1 (+) and the B gamma correction image F1 (−) are alternately displayed, for example, as shown in FIG. 11 (refer to Japanese Unexamined Patent Publication No. 2006-58891).
As shown in FIG. 12, in the black insertion mode, although the image blur caused by the hold effect may be improved, a luminance degradation is large. On the other hand, in the AB gamma correction mode, the image blur caused by the hold effect may be improved, and the luminance degradation is relatively small.
For example, in the case of moving image whose movement is active like TV sports program, the image difference between frames is large, and thus the movement of images may be seen unnatural with the usual frame rate (for example, 60 Hz). To solve this issue, for example as shown in FIG. 13B, there has been proposed a method which is a so-called high frame rate (HFR) mode in which an intermediate frame (F1+F2)/2 is generated on the basis of adjacent two image frames F1 and F2, and the intermediate frame is inserted between the frame F1 and the frame F2 so that the frame rate is increased twice. Furthermore, in FIG. 13A, there is shown a method (simple double-speed mode) in which each image frame is simply written twice, and thereby the frame rate is increased twice. As shown in FIG. 12, the HFR mode has a feature that moving images may be smoothly and naturally displayed.